CCR2 upregulated on peripheral T cells in osteoarthritis but not in bone marrow.

Osteoarthritis (OA) is a condition affecting millions of patients around the world, causing pain and disability and often resulting in joint replacement surgery. The aetiology of OA has long been attributed to mechanical wear mainly due to the increased prevalence of OA in load bearing joints among older patients. However, recent studies reveal a complex molecular disease causality in which inflammation, nutritional deficit and angiogenesis lead to the destruction of the joint structure. The aim of this study was to examine chemokine receptor expression in peripheral blood and bone marrow in OA patients. We devised a protocol for extracting healthy bone marrow from patients undergoing hip arthroplasty due to coxarthrosis. Flow cytometry was used to determine the expression of 18 chemokine receptors on CD4 and CD8 T cells from bone marrow and blood from 7 osteoarthritis patients and peripheral blood from 9 healthy controls. We found a significantly increased fraction of CCR2 expressing CD4 and CD8 T cell in peripheral blood compared to healthy controls. Also, there was a significant decrease in CXCR3 (Th1) (P < 0.01) expressing T cells in peripheral blood from OA patients. Finally, multivariate analysis was used to separate T cell profiles from healthy controls and OA patients and demonstrate that the divergence of chemokine receptor expression occurs in the mature T cell subsets. In conclusion, we find increased CCR2 expression in peripheral blood from OA patients that possibly may be targeted in future clinical studies.

Chemokine receptor expression on monocytes from healthy individuals.

Chronic immune mediated inflammation is characterized by continuous chemokine mediated recruitment and activation of pro-inflammatory cells, monocytes in particular. We believe that an evaluation of the recruitment profile of monocytes during healthy condition is essential for the understanding of cellular response in disease. For this, we have established normal reference values and 95% confidence intervals for receptor expression of 20 chemokine receptors on monocyte subsets; classical (CD14+ CD16−), non-classical (CD14+ CD16+) and HLA-DRhi monocytes from 20 healthy controls using flow cytometry. We demonstrate significant differences in the chemokine receptor expression profiles and high correlation between fraction of cells and level of expression. This is the first global approach to provide a platform for comparable evaluation of cell recruitment during normal and under inflammatory conditions. This will be useful when exploring chemokine­chemokine receptor interactions, inhibition of chemokine signaling and selective removal of migrating cells, which are new treatment strategies in immune mediated diseases.

Naïve T cells correlate with mucosal healing in patients with inflammatory bowel disease.

BACKGROUND: In previous studies, adaptive immune responses involving T-helper cells have been shown to play an important role in inflammatory bowel diseases (IBDs). METHODS: The aim of this study was to investigate any correlation between the degree of mucosal inflammation and the phenotype of gut-infiltrating T-helper cells. Biopsies from intestinal mucosa were obtained and intestinal T cells were analyzed with regard to activity and maturation markers. Patients with active colitis (39 with Crohn's disease and 47 with ulcerative colitis) were included and treated with corticosteroids, biologicals or leukocytapheresis. Flow cytometry was used to analyze activation marker expression on gut-infiltrating T-helper cells. RESULTS: Mucosal healing was reflected by almost 100% increase of CD62L expression in mucosal T cells in patients in remission compared to those with active inflammation (p < 0.01). The frequency of mucosal-naïve CD4(+)CD45RA(+) T cells was reduced by 50% in mucosa displaying remission (5.3% compared to 12% of the total amount and CD4(+) T cells, p < 0.001). Surprisingly, the proportion of early activated T-helper cells (CD4(+)CD69(+)) did not differ between mucosa in remission and non-remission (43% and 42%, respectively). Moreover, no change in memory T-helper cells (CD4(+)CD45RO(+)) was observed (64% compared to 66%). The findings were independent of diagnosis (Crohn's disease or ulcerative colitis) or mode of treatment. CONCLUSION: This study suggests that a reduced recruitment of naïve T-helper cells and increased frequency of T-helper cells with lymph node homing marker expression reflect mucosal healing in IBD. Surprisingly, the degree of activation of mucosal T-helper cells did not correlate with disease remission.

Profiling of CD4+ T cells with epigenetic immune lineage analysis.

Proper transcriptional control of pro- and anti-inflammatory responses of the immune system is important for a fine-tuned balance between protection and tolerance. Emerging evidence suggests a key role for epigenetic regulation in governing the Th cell differentiation, where effector cytokines direct the overall immune response. In this study, we describe a method to pinpoint the location of isolated human CD4(+) T cells on any T cell effector axis based on specific CpG methylation of cytokine and transcription factor loci. We apply the method on CD4(+) cells obtained from rheumatoid arthritis and multiple sclerosis patients and show that synovial fluid infiltrating CD4(+) T cells are committed toward both Th1 and regulatory T cell phenotype, whereas the Th2 response is suppressed. Furthermore, we show that the IL-17A gene is regulated by promoter methylation and that Th17 commitment is not a common feature in the inflamed joints of rheumatoid arthritis patients. We conclude that the method described in this paper allows for accurate profiling of Th lineage commitment in ex vivo-isolated CD4(+) T cells.

Urinary Bladder Cancer Tregs Suppress MMP2 and Potentially Regulate Invasiveness.

Regulatory T cells (Treg) have long been considered one-sided suppressors of antitumor immune responses and hence associated with poor patient outcome in cancer. However, evidence is mounting of a paradoxical positive prognostic effect of Tregs on certain malignancies, including urinary bladder cancer (UBC). This discrepancy has partly been attributed to the shear misidentification of Tregs, but also to the inflammatory profile of the tumor. Our aim was to determine whether tumor-infiltrating Forkhead box P3+ (FOXP3+) cells confer a stable Treg phenotype and to investigate putative beneficial Treg functions, focusing on tumor-promoting inflammatory pathways in UBC. Patients (n = 52) with suspected UBC were prospectively included. We show, by using a broad range of analytical approaches, that tumor-infiltrating CD4+FOXP3+ T cells in UBC phenotypically, functionally, and epigenetically represent a true Treg population. At the invasive front of UBC tumors, we found an inverse relationship between Treg frequency and expression of matrix metalloproteinase 2 (MMP2), a key proinvasive factor induced by tumor-promoting inflammation. Correspondingly, a significant, dose-dependent Treg-mediated downregulation of MMP2 protein and mRNA expression was observed in both macrophages and UBC cells. Also, we found that Treg frequency specifically at the invasive front positively correlated with survival. Thus, we identify Treg-mediated suppression of MMP2 in the tumor microenvironment as a mechanism explaining the paradoxical positive prognostic impact of tumor-infiltrating Tregs in UBC. Cancer Immunol Res; 6(5); 528-38. ©2018 AACR.

Increased CD4+ T cell lineage commitment determined by CpG methylation correlates with better prognosis in urinary bladder cancer patients.

BACKGROUND: Urinary bladder cancer is a common malignancy worldwide. Environmental factors and chronic inflammation are correlated with the disease risk. Diagnosis is performed by transurethral resection of the bladder, and patients with muscle invasive disease preferably proceed to radical cystectomy, with or without neoadjuvant chemotherapy. The anti-tumour immune responses, known to be initiated in the tumour and draining lymph nodes, may play a major role in future treatment strategies. Thus, increasing the knowledge of tumour-associated immunological processes is important. Activated CD4+ T cells differentiate into four main separate lineages: Th1, Th2, Th17 and Treg, and they are recognized by their effector molecules IFN-γ, IL-13, IL-17A, and the transcription factor Foxp3, respectively. We have previously demonstrated signature CpG sites predictive for lineage commitment of these four major CD4+ T cell lineages. Here, we investigate the lineage commitment specifically in tumour, lymph nodes and blood and relate them to the disease stage and response to neoadjuvant chemotherapy. RESULTS: Blood, tumour and regional lymph nodes were obtained from patients at time of transurethral resection of the bladder and at radical cystectomy. Tumour-infiltrating CD4+ lymphocytes were significantly hypomethylated in all four investigated lineage loci compared to CD4+ lymphocytes in lymph nodes and blood (lymph nodes vs tumour-infiltrating lymphocytes: IFNG -4229 bp p < 0.0001, IL13 -11 bp p < 0.05, IL17A -122 bp p < 0.01 and FOXP3 -77 bp p > 0.05). Examination of individual lymph nodes displayed different methylation signatures, suggesting possible correlation with future survival. More advanced post-cystectomy tumour stages correlated significantly with increased methylation at the IFNG -4229 bp locus. Patients with complete response to neoadjuvant chemotherapy displayed significant hypomethylation in CD4+ T cells for all four investigated loci, most prominently in IFNG p < 0.0001. Neoadjuvant chemotherapy seemed to result in a relocation of Th1-committed CD4+ T cells from blood, presumably to the tumour, indicated by shifts in the methylation patterns, whereas no such shifts were seen for lineages corresponding to IL13, IL17A and FOXP3. CONCLUSION: Increased lineage commitment in CD4+ T cells, as determined by demethylation in predictive CpG sites, is associated with lower post-cystectomy tumour stage, complete response to neoadjuvant chemotherapy and overall better outcome, suggesting epigenetic profiling of CD4+ T cell lineages as a useful readout for clinical staging.

Randomised, Double-blind, Placebo-controlled Trial of CCR9-targeted Leukapheresis Treatment of Ulcerative Colitis Patients.

BACKGROUND AND AIMS: Ulcerative colitis patients display increased numbers of circulating pro-inflammatory monocyte human leukocyte antigen-DR [HLA-DRhi] monocytes expressing high levels of the gut-homing C-C chemokine receptor 9 [CCR9] and tumour necrosis factor [TNF]-α. The aim of this first-in-human, double-blind, randomised, placebo-controlled trial was to evaluate selective removal of circulating CCR9-expressing monocytes by leukapheresis in patients with moderate to severe ulcerative colitis, with regards to safety, tolerability, and immunological response. METHODS: Patients with ulcerative colitis were treated every second day with leukapheresis during five sessions with a C-C chemokine ligand 25 [CCL25; CCR9 ligand] column or a placebo column. RESULTS: No major safety concerns were raised and the procedure was well tolerated. Pro-inflammatory HLA-DRhi cells decreased significantly in the active treatment group [p = 0.0391] whereas no statistically significant change was seen in the placebo group [p = 0.4688]. There was a significant decrease of HLA-DRhi monocytes in the active group compared with the placebo group when corrected for the imbalance in weight between the groups [p = 0.0105]. Mayo score decreased in the active group [p = 0.0156] whereas the change in the placebo group was not significant [p = 0.1250]. Mayo score ≤ 3 was observed in five out of 14 patients [35.7%] in the active group compared with one out of eight [12.5%] receiving placebo. The number of responders in the active treatment group was eight out of 14 patients [57.1%], whereas in the corresponding placebo group three out of eight patients [37.5%] responded to placebo. A dose-response correlation was observed between the blood volume processed and clinical outcome. CONCLUSION: This clinical induction trial using CCL25-tailored leukapheresis demonstrates a safe and effective removal of activated monocytes with a clinical effect in patients with ulcerative colitis.

HLA-DR(hi) and CCR9 Define a Pro-Inflammatory Monocyte Subset in IBD.

OBJECTIVES: It has been demonstrated that circulating monocytes relocate to the intestinal mucosa during intestinal inflammation, but the phenotype and inflammatory mechanisms of these monocytes remain poorly understood. Here, we have investigated blood monocytes expressing high levels of HLA-DR and CCR9 in patients with inflammatory bowel disease (IBD). METHODS: Fifty-one patients with mild to severe ulcerative colitis (UC; n=31; UC-DAI 3-12) or Crohn's disease (CD; n=20; Harvey-Bradshaw indices (HBI) 2-16) were included together with 14 controls, during IBD therapy for four consecutive weeks. The frequency of CD14(+)HLA-DR(hi) monocytes was monitored weekly in peripheral blood, using flow cytometry. The surface phenotype and cytokine profile of these monocytes were established using flow cytometry and real-time PCR. Clinical parameters were assessed weekly in all patients. RESULTS: The frequency of circulating CD14(+)HLA-DR(hi) monocytes was significantly higher in IBD patients with moderate to severe disease compared with healthy controls (P<0.001). During treatment with corticosteroids and granulocyte/monocyte apheresis, the proportion of circulating CD14(+)HLA-DR(hi) monocytes was significantly reduced. CD14(+)HLA-DR(hi) monocytes produced high levels of inflammatory mediators, such as tumor necrosis factor (TNF)-α, and expressed the gut-homing receptor CCR9. Furthermore, we found that the CCR9 ligand, CCL25/TECK, was expressed at high levels in the colonic mucosa in IBD patients with active disease. CONCLUSIONS: CD14(+)HLA-DR(hi) blood monocytes were increased in patients with active IBD. These monocytes exhibit a pro-inflammatory, gut-homing phenotype with regard to their TNF-α production and expression of CCR9. Our results suggest that these monocytes are important in mediating intestinal inflammation, and provide potential therapeutic targets in IBD.